PITTSBURGH -- Center fielder Lorenzo Cain is returning to Kansas City for another look at the torn hip flexor that has put him on the disabled list and recovering at the Royals' camp in Surprise, Ariz.

"He's been sent back to Kansas City, but it's not a serious thing. I think he's slated to go out on [Minor League] rehab next week sometime," manager Ned Yost said.

Cain began the season as the Royals' starting center fielder and his troubles began in the fifth game on April 10 at Oakland, when he banged into the wall while making a catch. He went on the disabled list with a left groin strain and later was sent on a rehab assignment with Double-A Northwest Arkansas.

In just his third game with the Naturals on April 24, Cain suffered a left hip flexor tear when he broke back for a fly ball. At the time, Cain was told he'd be out four to eight weeks. He's been at Surprise ever since and has missed 53 of the Royals' games.

"I forget how long it has been, I didn't realize that it's been that long," Yost said.

Hosmer back at first for finale with Pirates

PITTSBURGH -- Eric Hosmer and Mike Moustakas entered the visitors' clubhouse at PNC Park on Sunday morning, looked at the Royals' lineup card on the bulletin board, then exchanged a fist bump.

"Just like old times," Moustakas said with a smile.

What he meant was that his buddy, Hosmer, was back across the infield at first base for Sunday's Interleague series finale against the Pirates. Hosmer had played right field in the first two games, a move that proved defensively costly, notably with a botched bounce for an error and a missed looper that appeared catchable.

The move was made so that designated hitter Billy Butler could move to first base to keep his bat in the lineup. Butler showed his vulnerability, too; he booted one grounder and recovered to get an out but still ...

"We've got to try to play a defensive game," manager Ned Yost said. "I tried it and I don't think it's going to work. But I had to try it."

But on Sunday, Hosmer was back at first base and Butler was out of the lineup. Still ahead are six Interleague games in National League cities -- three at St. Louis and three at Houston -- so if that approach holds, either Butler or Hosmer would have to be out of the lineup in those games.

"I'll continue to think through it, but I'm leaning that way," Yost said.

Also on Sunday, Yost decided to sit Jeff Francoeur and Yuniesky Betancourt because they had not hit well against Pirates starter A.J. Burnett. So Jarrod Dyson played center field where Francoeur had been stationed, Mitch Maier played right field and Johnny Giavotella replaced Betancourt at second base.

"Guys got some days off today and I think he shuffled the lineup a little bit. But we've got another week of Interleague away games, so hopefully I'll get another chance out there," Hosmer said. "I'm starting to get more comfortable out there."

Hosmer realizes that becoming a proficient outfielder does not happen overnight.

"First base took me about 22 years to be semi-good at it, so hopefully I'll get a little more time out there in the outfield and we'll see what happens," he said.

Royals bracing for Greinke's return to KC

PITTSBURGH -- When the Royals take the field against the Brewers' Zack Greinke on Tuesday night in Kansas City, they know they'll have their work cut out for them.

Catcher Brayan Pena, who was Greinke's KC teammate for two years, learned how badly the pitcher wants to win -- on the field and in the clubhouse.

"He liked to compete," Pena said. "We played chess together, we played poker, whatever we were playing, he wanted to win. He learned how to play Spanish dominoes, too. He said we're very passionate about the dominoes, so he wanted to learn how to play. He was very good, too -- [Jose] Guillen taught him how to play."

Pena was a backup catcher in 2009 when Greinke won the American League Cy Young Award.

"Greinke was something special," Pena said. "He taught me a lot of stuff. It was a learning experience with Zack every time that I caught him. The fact that he trusted me to call games -- especially the year that he won the Cy Young. I had a chance to catch him a little bit -- [Miguel] Olivo caught him a lot -- and he was very smart. If he makes a mistake, you'll rarely see him make the same mistake twice. He studies the game from top to bottom and goes about his business very quietly."

Toney final piece to Royals-Astros trade

PITTSBURGH -- The deal that brought catcher Humberto Quintero and outfielder Jason Bourgeois to the Royals from the Astros has finally been completed.

The March 20 deal netted Houston left-handed pitcher Kevin Chapman and a player to be named. That player is Minor League outfielder D'Andre Toney, the Royals announced on Sunday.

Toney, 20, was on the Rookie classification roster at Surprise, Ariz., and has been assigned to the Greeneville Astros of the Appalachian League. Toney was selected by the Royals in the 14th round of the 2011 First-Year Player Draft out of Hardaway High School in Columbus, Ga.

Last year for Surprise, the right-handed Toney hit .340 in 43 games with five homers, five triples, 12 doubles, 29 RBIs and seven stolen bases.

Quintero is sharing the Royals' catching duties and has a .230 average in 33 games. Bourgeois is batting .195 in 32 games for Triple-A Omaha. Chapman, pitching in relief for the Astros' Double-A club at Corpus Christi, is 3-2 with a 2.30 ERA in 24 games.